Magnetic head assemblies that fly relative to rotating magnetic disks are used extensively in disk drives for recording or reading data. Air bearing sliders used in these head assemblies typically have a leading edge and a trailing edge. One or more magnetic transducers are deposited at the trailing edge of the slider. Generally, the sliders have tapered portions at the leading edge and longitudinal rails that extend from the tapers all or part way to the trailing edge.
The processing methods used in fabricating air bearing sliders begin with conventional full-wafer processing techniques, which are used to form the magnetic transducing elements at the trailing edge of the slider. In order to implement the process which forms the air bearing slider structure, the full wafer must be sliced into rows to expose the cross-section of the wafer upon which the slider structure is to be formed. These rows are aligned and fixed onto a substrate, and then conventional patterning and etching techniques are used to form the slider rail structure. Both horizontal alignment of the rows and vertical alignment of the surfaces to be processed into sliders are critical, the latter for providing uniformity of etch depth.
Protecting the exposed vertical edge of the slider, where the transducer has been deposited, is critical during etching of the slider, which is normally accomplished using reactive ion etching (RIE) or ion milling techniques. Typically, when the vertical edges of the slider are protected by layers of photoresist during etching, tearing of the photoresist on the vertical edges often leaves the active devices exposed to the RIE plasma. One consequence is chemical redeposition on the active devices during etch. To minimize such effects, thick layers of negative resist must be used with all the inherent problems, such as poor critical dimension (CD) control, poor resolution and the like.
Cutting the rows into individual sliders after the air bearing etch presents further problems. If the rows must be debonded from the etch substrate and rebonded onto a second substrate before cutting, known as the partoff/rebonding operation, contamination due to handling and processing time are increased. Thus, an optimized process would eliminate the debonding entirely and permit the cutting of the individual sliders while the rows were still bonded to the etch substrate.
Desirable properties of an adhesive which bonds the rows to the etch substrate are: 1) it should cure completely and quickly; 2) It should have high thermal conductivity to minimize the rise in temperature of the devices during the air bearing etch; 3) it should be resistant at least in the short term to the photoresist stripper; and 4) it should leave no residue when removed from the rows of devices.